This invention relates to a magnetic recording and reproducing system, specifically equipped with a cleaning mechanism to prevent its rotary magnetic head from clogging. For example, in household VTR units, a so-called helical scanning method is generally used wherein magnetic tape is helically wound approximately 180 to 220 degrees around a cylinder having a rotary magnetic head. Such units include those for recording and reproduction of magnetic tape and those for only recording such as an integrated type of VTR camera. In this specification, these units are comprehensively called as magnetic recording and reproducing systems. In such magnetic recording and reproducing systems using a rotary magnetic head, most deterioration of recorded or reproduced image or misrecording can be attributed to a clogged rotary magnetic head. Clogging of the rotary magnetic head is caused by dust in the atmosphere or magnetic powder produced while the magnetic head scans recording media. It is therefore necessary to frequently clean the magnetic head in order to assure good recording and reproduction.
Heretofore, the rotary magnetic head has been cleaned using a cleaning cassette which is a cleaning tape installed in a cassette or by walline silicon layer containing oxygen is formed on the first polycrystalline silicon layer. And then, an oxide formed between the two polycrystalline silicon layer is removed by annealing.